Absence of carrier specificity in an adoptive secondary response.

Different NIP (4-hydroxy-3-iodo-5-nitrophenylacetic acid) conjugates were used to study carrier specificity in normal and adoptive secondary responses. When rats were primed with NIP—HSA conjugate and boosted with either NIP—HSA or NIP—CG 45 days later, there was a clear carrier specificity; the homologous carrier caused a stronger response than the heterologous carrier. When the interval between the first and the second injection was extended to 4 months, carrier specificity was much less strict. Adoptive secondary responses were not carrier-specific whether the time between the priming injection and transfer plus restimulation was short (21 days) or long (4 months). Adoptive secondary IgM responses were less dependent on stimulation with the homologous carrier than the simultaneous IgG responses of the same animal.